Extract-stent-replace for treatment of upper baffle stenosis with pacing leads after atrial switch procedures for transposition of the great arteries: An approach to avoid "jailing" the lead.

INTRODUCTION: Venous stenosis is a late complication of the atrial switch (Mustard/Senning) procedure seen in patients with transposition of the great arteries ( d-TGA). Many atrial switch patients require cardiac implantable electronic devices (CIEDs) which further increases the incidence of venous stenosis. Stenosis of the superior limb of the systemic venous pathway (SLSVP) in the presence of CIED leads presents a management challenge. We propose a method for navigating SLSVP stenosis in atrial switch patients with CIEDs. METHODS: The pulse generator and leads were removed using standard extraction techniques. Axillary access was retained via existing leads or new access was obtained. The interventional cardiology team, via groin access, performed stent-angioplasty of the stenotic SLSVP. After stent deployment, the axillary access wire was snared from below, guided through the stent, and pulled into a long groin sheath. A sheath was then advanced over the axillary wire and into the groin sheath creating a path for passage of leads through the stent. New leads were advanced through the axillary sheath into the heart. Leads were secured using standard techniques. RESULTS: All patients had a history of d-TGA and prior atrial switch procedures. In each case, there was stenosis of the SLSVP in the setting of a CIED lead. There were no immediate complications and there was no restenosis on follow-up. CONCLUSION: Post-atrial switch patients with CIEDs can develop stenosis of the SLSVP. A collaboration between electrophysiology and interventional cardiology can allow for device extraction, stent-angioplasty, and lead reimplantation to avoid "jailing" the leads.

Effectiveness of Early Invasive Therapy for Atrial Tachycardia in Adult Atrial-Baffle Survivors.

Adults who underwent complex atrial baffling as children via Mustard or Senning procedures are at heightened risk for atrial arrhythmias. Antiarrhythmic therapies are typically ineffective in this population. Accordingly, our team of pediatric and adult electrophysiologists investigated the effectiveness of early invasive transbaffle-access techniques to perform early radiofrequency ablation at the source of these clinically significant arrhythmias. For this retrospective study, we selected 11 adult survivors of atrial baffling (mean age, 34 ± 9 yr) who underwent clinically indicated electrophysiologic study after no more than one trial of antiarrhythmic therapy. Using transbaffle-access techniques and 3-dimensional mapping of the venous atria, we found 12 inducible arrhythmias in 10 patients: intra-atrial reentrant tachycardia (n=6), atrioventricular nodal reentrant tachycardia (n=3), focal atrial tachycardia (n=2), and repetitive double firing of the atrioventricular node (n=1). Defining success as short- and midterm freedom from arrhythmia, we analyzed outcomes of radiofrequency ablation at 1 and 6 months. At 1 month, ablation was 100% successful. At 6 months, after 11 ablations in 9 patients, 5 patients had no clinical recurrence, 2 had improved arrhythmia control from minimal medical therapy, and 2 were to undergo repeat study for recurrent tachycardia. In the recurrence-free patients, arrhythmias during electrophysiology study matched the types found clinically before the study. To our knowledge, this is the largest one-year cohort of adult survivors of atrial baffling to have undergone study by a combined pediatric-adult electrophysiology team. We conclude that early invasive transbaffle access for ablating diverse atrial tachyarrhythmias was effective in these patients.

Nonfluoroscopic Imaging as Guidance for Radiofrequency Ablation of Atrioventricular Nodal Reentrant Tachycardia after Mustard Repair.

Most tachycardias in the pulmonary venous atrium are inaccessible by direct means and require either a retrograde approach or a transseptal approach for ablation. We present a case in which successful radiofrequency ablation of common atrioventricular nodal reentrant tachycardia was accomplished via a retrograde transaortic approach guided by nonfluoroscopic mapping with use of the NavX™ mapping system. The patient was a 49-year-old woman who at the age of 4 years had undergone Mustard repair for complete dextrotransposition of the great arteries. Three-dimensional reconstructions of the ascending aorta, right ventricle, systemic venous atrium, left ventricle, and superior vena cava-inferior vena cava baffle complex were created, and the left-sided His bundle was marked. After a failed attempt at ablation from the systemic venous side, we eliminated the atrioventricular nodal reentrant tachycardia by ablation from the pulmonary venous side. This case is, to our knowledge, the first report of successful radiofrequency ablation of common atrioventricular nodal reentrant tachycardia after Mustard repair for this congenital cardiac malformation in which ablation was guided by 3-dimensional nonfluoroscopic imaging. This imaging technique enabled accurate anatomic location of the ablation catheters in relation to the His bundle marked from the systemic venous side.

Mechanisms and predictors of recurrent tachycardia after catheter ablation for d-transposition of the great arteries after the Mustard or Senning operation.

BACKGROUND: The Senning and Mustard operations for dextro-transposition of the great arteries are associated with an increased risk for supraventricular tachycardia. Catheter ablation has been shown to be acutely successful for achieving rhythm control in this population, but the mechanisms of recurrence are ill-defined. OBJECTIVE: We hypothesized that the type and degree of recurrence would vary by the surgical technique used. METHODS: All consecutive catheter ablation procedures for dextro-transposition of the great arteries after the Mustard or Senning operation between 2004 and 2016 at a single center were reviewed. Tachycardia mechanisms were determined by complete 3-dimensional mapping in addition to a standard electrophysiological technique for all cases. RESULTS: Twenty-eight patients underwent 38 procedures during the study period. The most common mechanism at the index procedure was intra-atrial reentrant tachycardia using the cavotricuspid isthmus. Over a median follow-up period of 1.6 years, 9 patients experienced recurrent tachycardia (32%), all of whom underwent repeat catheter ablation. Tachycardia recurrence was more common after the Senning vs the Mustard operation (6 of 10 [60%] vs 3 of 18 [17%]; P = .034). In addition, substrates for recurrence were different from those encountered at the index procedure in 10 of 13 tachycardias (77%), with the single most common location being the posterior anastomosis after the Senning operation. Complete control was ultimately achieved in 27 patients (96%) when considering all procedures. CONCLUSION: Recurrent tachycardia after catheter ablation appears to be more common after the Senning operation and to involve substrates unique to this repair. The posterior anastomosis is commonly implicated and should not be overlooked.

Hemodynamic assessment with interventional support should be routine for primary electrophysiology procedures after atrial switch procedure.

OBJECTIVES: We sought to review our current philosophy that all primary invasive electrophysiologic (EP) studies in patients with atrial switch procedures (ASPs) should undergo hemodynamic evaluation and have interventional expertise available. BACKGROUND: Patients who have undergone an ASP for dextro-transposition of the great arteries have a high incidence of both hemodynamic and EP sequelae. We present our data to support the combined assessment approach for these patients. METHODS: Hemodynamic evaluation and interventions performed concurrently during a primary invasive EP procedure in patients with ASP were reviewed. RESULTS: A total of 18 patients underwent concurrent EP invasive procedure and cardiac catheterization. The median age was 31 (14-43 years) with the majority being male (67%). Patients underwent a total of 30 concurrent primary invasive EP procedure and cardiac catheterization; 14 (47%) of the catheterization procedure were interventional. Some of the catheterization procedures required more than one intervention with total of 19 separate interventions. There were nine (47%) unexpected interventions. The majority of patients (n = 14, 77.8%) had one or more abnormal hemodynamic finding including baffle obstruction (n = 13, 72%), elevated filling pressures (n = 3, 17%), and secondary pulmonary hypertension (n = 3, 17%). Non-EP-related interventional procedures included systemic or pulmonary venous baffle stenting for significant obstruction (n = 7). EP-related interventions included transbaffle puncture for ablation of left-sided reentry circuits (n = 5), closure of previously undiagnosed baffle leaks prior to pacemaker/implantable cardioverter defibrillator (ICD) placement to prevent paradoxical embolism (n = 3), superior baffle stenting to facilitate pacemaker/ICD lead placement (n = 2), and retrieval of retained transvenous pacemaker/ICD lead (n = 2). CONCLUSION: Due to the frequency of abnormal hemodynamics or interventional needs, strong consideration for routine concurrent hemodynamic assessment and availability of interventional expertise is warranted during primary invasive EP procedures in patients post ASP.